Spark-plug.



G. .I. KNUTSON.

SPARK PLUG.

APPLLCATIQN, FILED use. 2, 19:4.

1,1 98,358. Patehted Sept. 12,1916.

i/9 14M o w UNITED STATES PATENT OFFICE.

GILBERT J. KNUTSON, OF SALMON, WASHINGTON.

SPARK-PLUG.

Specification of Letters Patent.

Patented Sept. 12,1916.

Application filed December 2, 1914. Serial No. 875,142.

skilled in the art to which it appertains to.

make and use the same.

This invention relates to certain novel and useful improvements in spark, plugs. e

In carrying out my invention it is my purpose to provide a spark plug which is adapted particularly for use in connection with gasor gasoline engin cylinders and through the medium of which a series of sparks may be produced to insure the proper ignition and explosion.

Still a further object of my invention is the provision of a spark plug having a plurality of sparking points capable of producing what may be termed a multiple spark, thereby insuring a more perfect explosion of the gases and increasing the power produced as the result thereof, in the sense that as the explosion is more perfect, less gas is consumed and the engine more easily kept clean, thereby increasing its efiiciency.

A further object of the invention is the provision of a spark plug of this character which will embodythe desired features of simplicity, efliciency and reliability, and which maybe manufactured and marketed at a relatively low cost.

With the above recited objects and others of a similar nature in view, my invention consists in the construction, combination and arrangement of parts set forth in and falling within the scope of the appended.

claims. I

In the accompanying drawings: Figure 1 is a vertical longitudinal sectional view,

taken through a spark plug embodying my invention. Fig. 2 is a vertical sectional view taken through the core of the plug and showing the electrode wire before the coil thereof has been cut or severed. Fig. 3 is an end view of Fig. 1 and showing the sparking terminals. Fig. 4 is a detail perspective view of the wire forming the upper electrode before the wire thereof is severed to form the sparking terminals or tips.

Referring now to the accompanying drawings in detail, the letter A designates the metallic casing or shell of the plug,

which may be of any suitable construction,

and is externally threaded as at 1 to screw into the head of the engine cylinder in the ordinary and well known manner. This shell or casing is internally shouldered'as at 2, and is furthermore internally threaded at its outer end as at 3. The numeral 4 indicates the core of the plug which is formed of suitable insulating material, such as porcelain or the like. This core is shouldered as at 5 to rest upon the shoulder 2 of the shell, while this core is furthermore pro vlded with an upper shoulder 6 against which the lower end of the bushing 7 is adapted to bear, this bushing being exter nally threaded as at 8 to thread into the upper end of the shell. Thus it will be seen that the core is firmly held within the shell.

Embedded in the core'is a wire w, comprising a shank section 9 which extends through the top of the electrode and is adapted to be connected with the usual battery. This wire is shown in detail in Fig. 4, and it will be seen that the lower; end thereof is formed with a plurality of longitudinally extending elliptical loops indicated at 10. In the manufacture of the core, the major portion of the loops are embedded therein as shown in Figs. 1 and 2, that is to say the lower loop portion of the wire is embedded in the core preferably approximately about three-fourths of its lengt the lower portion of the looped section of the wire projecting beyond the bottom 4 of the core. In the construction of the spark plug, thelwire.

after it has been embedded in the core, is severed at the lower ends of the loops at the points 12 and 13, so that two spark gaps are formed at these points 12 and 13. The

free end 14 of the wire is spaced apart from the ground electrode 15, so that a; gap 16 is formed between such ground electrode and the free terminal 14 of the wire. This ground electrode 15 is socketed in the shell 1, and as this latter is ofcontacting material,

this electrode 15 is, of course, grounded at the engine cylinder.

current as it goes, down the wire jumping in a spark across the gap 12, thence running around the front loop 10, thence jumping and sparking at the gap 13 and passing through the second loop and thence .jumping and sparking at the gap 16 on its way to the ground electrode 15. By such a construction a very eflicient spark plug is produced in which the sparks are clear and sharp, so that the ignition of the gases in the engine cylinder at the proper times is rendered positive and certain.

What I claim is:

1. A spark plug having its electrode formed of a coil of metal wire adapted to be included in a sparking circuit, the wire being parted at intervals in the formation of sparking gaps, and the resultant sections of the wire being held in fixed mutual insulated relation.

2. In a sparking plug the combination with a shell and a core of insulating material, of an electrode carried by the shell and consisting of a wire including a plurality of coils anchored in the core and having portions exposed, an exposed portion of each coil being parted with resultant sparking terminals, the shell having a sparking terminal cooperating with said electrode.

3. In a spark plug the combination with a shell and an electrode carried thereby, a coil of insulating material arranged within the shell and a wire comprising a shank and a plurality of loops carried by the core in axial alinement, said shank and portions of the loop being embedded in the core, the remaining portions of the loop being exposed and each being parted to form a plurality of sparking terminals.

In testimony whereof, I affix my signature, in the presence of two witnesses.

GILBERT J KNUTSON.

\Vitnesses:

GEO. K. RANKIN, AVERY R. HAYES. 

